A non-invasive opening angle monitoring device and method based on magnetic sensing

Abstract

The application provides a non-invasive window opening angle monitoring device and method based on magnetic sensing. The device converts the window opening movement into in-plane rotation of the guide tube and axial reciprocating sliding of the plug-in sliding shaft through the mechanical transmission module installed between the window sash and the window frame. The magnetic sensing module fixed on the wall side detects the magnetic field change signal generated by the rotating magnet in real time. The signal is calculated by the microcontroller integrated in the single control and communication module. Based on the geometric parameters such as the relative distance of the key module installation and the rotation angle signal, the actual opening angle is accurately calculated, and the data with time stamp is uploaded to the cloud Internet of Things platform through the wireless communication unit to realize online remote monitoring and analysis of the window opening behavior. The application has simple structure, clear module composition and can realize high-precision and continuous opening degree monitoring. The structure of the application is suitable for green buildings and is used for accurately obtaining user behavior data and predicting building indoor energy consumption.

Description

Technical Field

[0001] This invention relates to the fields of intelligent energy-saving technology for green buildings and indoor environmental monitoring technology, and in particular to a non-invasive window opening angle monitoring device and method based on magnetic sensing. The device and method are applicable to the accurate and continuous online monitoring and remote data acquisition of casement window openings in the indoor environments of high-performance buildings such as green buildings, passive buildings, and near-zero energy buildings, providing key data support for building energy consumption optimization, natural ventilation control, and green building certification. Background Technology

[0002] Window opening status not only affects indoor air circulation and thermal performance, but is also closely related to building energy management, indoor air quality, natural ventilation efficiency, and occupant comfort. In green building operation and management, accurately controlling window opening status and angle is of great significance for building energy consumption monitoring and optimization, natural ventilation effect assessment, indoor environmental quality control, and intelligent energy-saving control.

[0003] In existing IoT-integrated smart building environments, window opening monitoring or detection methods mainly include mechanical limit switch detection, displacement sensor detection, optical or ultrasonic ranging detection, and inertial measurement unit (IMU) detection.

[0004] Mechanical limit switch detection can typically only determine the "open" or "closed" state of the window sash, and cannot obtain continuous opening angle information; attached displacement sensors or potentiometers require drilling or pasting on the window sash surface, which is highly invasive, affects aesthetics, and has poor long-term stability; photoelectric / ultrasonic ranging methods are limited by installation space, ambient light, and obstructions, and the measurement accuracy and reliability are easily affected by external factors; although IMU sensors can measure angular velocity and acceleration, they require periodic calibration to eliminate zero drift and temperature drift, the algorithm implementation is complex, and the installation direction is strictly required.

[0005] The aforementioned technologies have significant shortcomings in terms of accuracy, reliability, ease of installation, and low invasiveness. They are insufficient to meet the real-time monitoring requirements for window opening in scenarios such as green building energy consumption optimization, automated indoor environment regulation, and natural ventilation effect evaluation, which require high precision, long cycle, and low maintenance. This seriously affects the precise regulation of the indoor environment and the full realization of the energy-saving potential of green buildings. Summary of the Invention

[0006] The purpose of this invention is to address the problems in existing technologies by proposing a non-invasive window opening angle monitoring device and method based on magnetic sensing. This device features a simple structure, ease of installation, and does not damage the window structure. It enables real-time, continuous, and accurate measurement of window opening angles and can upload data to the cloud via wireless communication, meeting various application needs such as green building energy consumption monitoring, environmental control, and natural ventilation optimization.

[0007] This invention is achieved through the following technical solution: This invention proposes a non-invasive window opening angle monitoring device based on magnetic sensing. The device includes a mechanical transmission module, a magnetic sensing module, a control and communication module, and a power supply module. The base assembly of the mechanical transmission module is installed inside the window sash of a casement window and is connected to the magnetic sensing module fixed to one side of the wall of the window sash rotation axis. The signal input terminal of the magnetic sensing module and the control and communication module are electrically connected via wired connection. The signal output of the control and communication module is connected to a cloud server or IoT platform via a built-in wireless communication unit using the HTTP / MQTT protocol, and is powered by the power supply module via wired connection. Both are fixed in an ABS waterproof box and installed under the window opening sill.

[0008] Furthermore, the mechanical transmission module includes a base assembly, a hinge connector, a guide tube, and a T-shaped rotating shaft; the base assembly is fixedly installed on the window sash, and its position in the XY plane changes with the opening state of the window; the hinge connector hinges one end of the guide tube to the base assembly, allowing the guide tube to rotate in the plane about the central axis of the hinge connector; the short shaft of the T-shaped rotating shaft is inserted into the guide tube and can slide back and forth axially relative to the guide tube; the long shaft end of the T-shaped rotating shaft is fixed in a bushing shell on one side of the wall, and the bushing shell ensures that the T-shaped rotating shaft can only rotate in the horizontal plane and does not shift radially.

[0009] Furthermore, the magnetic sensing module includes a rotating magnet and a magnetic encoder; the rotating magnet is a cylinder, installed in a circular groove at the center of the bottom of the long axis of the T-shaped rotating shaft and rotates with it, its rotation center axis coincides with the rotation axis of the long axis of the T-shaped rotating shaft in the spatial Z direction, so its rotation angle is the same as that of the T-shaped rotating shaft; the magnetic encoder is built into a fixed housing box installed at the lower end of the bushing housing, and a hole is reserved for the wire to pass through.

[0010] Furthermore, the magnetic encoder is a radial induction magnetic encoder, whose sensing surface is arranged parallel to the axial end face of the rotating magnet and maintains a certain distance, detecting the magnetic field change of the rotating magnet and outputting a digital angle signal θ.

[0011] Furthermore, the magnetic encoder maintains a distance of 2–5 mm from the rotating magnet.

[0012] Furthermore, the control and communication module is an integrated unit, including a microcontroller unit and a wireless communication unit; the microcontroller unit has a built-in calculation algorithm based on window geometric parameters and displacement signals to calculate the real-time window opening angle; the wireless communication unit is integrated with the microcontroller unit, supports HTTP and MQTT wireless protocols, and sends the real-time window opening angle with timestamps to a cloud server or IoT platform.

[0013] Furthermore, the power supply module is a detachable lithium battery pack with overcharge, over-discharge and short-circuit protection circuits, and supplies power to the control and communication module and magnetic encoder via a linear connection through a power interface.

[0014] Furthermore, the base assembly is installed at the middle position along the length of the window sash, and the horizontal distance between the center line of the hinge connector axis and the center line of the window sash rotation axis is denoted as d; the horizontal distance between the center line of the long axis of the T-shaped rotation axis and the center line of the window sash rotation axis is denoted as r.

[0015] Furthermore, the solution algorithm built into the microcontroller unit is based on the following geometric relationship:

[0016]

[0017] Wherein, α is the real-time window opening angle; θ is the reading of the digital angle signal output by the magnetic encoder; r is the horizontal distance between the center line of the hinge connector axis and the center line of the window sash rotation axis; and d is the horizontal distance between the center line of the long axis of the T-shaped rotation axis and the center line of the window sash rotation axis.

[0018] The present invention also proposes a monitoring method based on the aforementioned window opening angle monitoring device, comprising the following steps:

[0019] S1. When the user opens the window sash, the base assembly in the mechanical transmission module changes position in the horizontal plane through the window sash, and drives the guide tube to rotate and causes the short shaft of the T-shaped rotating shaft to slide axially in the guide tube;

[0020] S2. The rotating magnet rotates synchronously with the T-shaped rotating axis and generates a measurable magnetic field change in the magnetic sensing module;

[0021] S3. The magnetic encoder acquires the magnetic field change signal and converts it into digital angle data, denoted as θ, which is then transmitted to the microcontroller unit;

[0022] S4. The microcontroller unit calculates the real-time window opening angle based on preset geometric parameters and the digital angle data θ using the calculation algorithm;

[0023] S5. The wireless communication unit uploads the real-time window opening angle and timestamp to a cloud server or IoT platform via a network protocol to achieve real-time remote monitoring and analysis of the window opening behavior.

[0024] The beneficial effects of this invention are:

[0025] 1. Non-intrusive installation: No need to damage the window structure, modular layout is achieved through the boundary between the wall and the window sash, easy to install, and does not affect the original window function;

[0026] 2. High precision and continuous monitoring: Based on magnetic encoder and geometric solution model, the measurement accuracy can reach ±1°, and continuous real-time monitoring is supported;

[0027] 3. Low power consumption design: Powered by a lithium battery, it has the ability to operate stably for a long time and is suitable for low maintenance scenarios;

[0028] 4. Remote data management capability: The device has wireless communication capabilities, supporting online monitoring, cloud storage, and subsequent data analysis;

[0029] 5. High adaptability: This invention can be adapted to different types of casement window structures by modifying geometric parameters, and has good scalability and versatility. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structural composition of the window opening angle monitoring device of the present invention, showing four modules and their connection methods;

[0032] Figure 2 This is a schematic diagram of the installation structure of the device of the present invention with the window closed, where r and d refer to distances.

[0033] Figure 3 This is a schematic diagram of the device described in this invention installed in a real scene;

[0034] Figure 4 This is a structural disassembly diagram of the device described in this invention;

[0035] Figure 5 These are three structural views of the base assembly, hinge connector, and guide tube installation in this invention.

[0036] Figure 6 The three views are of the T-shaped rotating shaft and the rotating magnet in the magnetic sensing module installed at the bottom in this invention.

[0037] Figure 7 These are three views of the structure of the T-shaped rotating shaft and bushing housing after installation of the present invention;

[0038] Figure 8 This is a schematic diagram of the measurement process of the window opening angle monitoring device in a real scenario in the implementation method of the present invention, showing the device deformation process and measurement process under different window opening scenarios;

[0039] Figure 9 This is a schematic diagram of the geometric relationship for calculating the window opening angle in this invention, indicating the parameters d, r, θ and the calculation result α.

[0040] The following are the reference numerals in the figure: 1. Base assembly; 2. Hinge connector; 3. Guide tube; 4. T-shaped rotating shaft; 5. Rotating magnet; 6. Bushing housing; 7. Fixed housing box; 8. Magnetic encoder; (9, 10) Control and communication module; 11. Removable lithium battery pack; 12. ABS waterproof box. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Combination Figures 1-9 This invention proposes a non-invasive window opening angle monitoring device based on magnetic sensing. The device includes a mechanical transmission module, a magnetic sensing module, a control and communication module, and a power supply module. The base assembly of the mechanical transmission module is installed inside the window sash of a casement window and is connected to the magnetic sensing module fixed to the wall on one side of the window sash's rotation axis. The signal input terminals of the magnetic sensing module and the control and communication module are electrically connected via wired connection. The signal output of the control and communication module is connected to a cloud server or IoT platform via a built-in wireless communication unit using the HTTP / MQTT protocol, and is powered by the power supply module via wired connection. Both are fixed to an ABS waterproof box and installed under the window opening sill.

[0043] The mechanical transmission module includes a base assembly, a hinge connector, a guide tube, and a T-shaped rotating shaft. The base assembly is fixedly installed on the window sash, and its position in the XY plane changes with the opening state of the window. The hinge connector hinges one end of the guide tube to the base assembly, allowing the guide tube to rotate in the plane about the central axis of the hinge connector. The short shaft of the T-shaped rotating shaft is inserted into the guide tube and can slide back and forth axially relative to the guide tube. The long shaft end of the T-shaped rotating shaft is fixed in a bushing shell on one side of the wall, and the bushing shell ensures that the T-shaped rotating shaft can only rotate in the horizontal plane and does not shift radially.

[0044] The magnetic sensing module includes a rotating magnet and a magnetic encoder. The rotating magnet is a cylinder that is installed in a circular groove at the center of the bottom of the long axis of the T-shaped rotating shaft and rotates with it. Its rotation center axis coincides with the rotation axis of the long axis of the T-shaped rotating shaft in the spatial Z direction, so its rotation angle is the same as that of the T-shaped rotating shaft. The magnetic encoder is built into a fixed housing box installed at the lower end of the bushing housing, and a hole is reserved for the wire to pass through.

[0045] The magnetic encoder is a radial induction type magnetic encoder. Its sensing surface is set parallel to the axial end face of the rotating magnet and maintains a certain distance. It detects the magnetic field change of the rotating magnet and outputs a digital angle signal θ to achieve high-precision sensing of magnetic field changes.

[0046] The magnetic encoder maintains a distance of 2–5 mm from the rotating magnet.

[0047] The control and communication module is an integrated unit, including a microcontroller unit and a wireless communication unit. The microcontroller unit has a built-in calculation algorithm based on window geometric parameters and displacement signals to calculate the real-time window opening angle. Specifically, the microcontroller unit receives the angle signal θ from the magnetic encoder and calculates the real-time window opening angle α based on the geometric parameters set during device installation (i.e., the horizontal distance d between the center line of the hinge connector and the window sash rotation axis, and the horizontal distance r between the center line of the T-shaped rotation axis and the window sash rotation axis). The wireless communication unit is integrated with the microcontroller unit and supports HTTP and MQTT wireless protocols to send the real-time window opening angle with timestamps to a cloud server or IoT platform.

[0048] The power supply module is a detachable lithium battery pack with overcharge, over-discharge and short-circuit protection circuits. It supplies power to the control and communication module and magnetic encoder via a linear connection through the power interface, which is convenient for daily maintenance and replacement and is suitable for low-power long-term operation scenarios.

[0049] The base assembly is installed at the middle of the window sash along its length. The horizontal distance between the center line of the hinge connector axis and the center line of the window sash rotation axis is denoted as d. The horizontal distance between the center line of the long axis of the T-shaped rotation axis and the center line of the window sash rotation axis is denoted as r.

[0050] The solution algorithm built into the microcontroller unit is based on the following geometric relationship:

[0051]

[0052] Wherein, α is the real-time window opening angle; θ is the reading of the digital angle signal output by the magnetic encoder; r is the horizontal distance between the center line of the hinge connector axis and the center line of the window sash rotation axis; and d is the horizontal distance between the center line of the long axis of the T-shaped rotation axis and the center line of the window sash rotation axis.

[0053] The modules of the window opening angle monitoring device work together in the following way: the base assembly of the mechanical transmission module is installed inside the window frame and moves in the XY plane as the window sash opens. It drives the guide tube to rotate through the hinge connector and pushes the short axis of the T-shaped rotating shaft inserted into the guide tube to slide axially; the magnetic sensing module supports the T-shaped rotating shaft through the bushing shell fixed to the wall, and the rotating magnet installed at the bottom of its long axis rotates synchronously with the shaft. The magnetic encoder detects the magnetic field change in real time and outputs a digital angle signal; the control and communication module receives the magnetic encoder signal through a wired connection, calculates the real-time window opening angle based on the built-in calculation algorithm, and uploads the timestamped data to the cloud through the wireless communication unit (supporting HTTP / MQTT protocol); the power supply module is a detachable lithium battery pack, which supplies power to the control and communication module and the magnetic encoder through a linear connection and has overcharge, over-discharge and short circuit protection functions.

[0054] Specifically, the present invention also proposes a monitoring method based on the aforementioned window opening angle monitoring device for use in the field of green building, comprising the following steps:

[0055] S1. When the user opens the window sash, the base assembly in the mechanical transmission module changes position in the horizontal plane through the window sash, and drives the guide tube to rotate, causing the short shaft of the T-shaped rotating shaft to slide axially in the guide tube, and the long shaft to rotate accordingly.

[0056] S2. The rotating magnet rotates synchronously with the T-shaped rotating axis and generates a measurable magnetic field change in the magnetic sensing module;

[0057] S3. The magnetic encoder acquires the magnetic field change signal and converts it into digital angle data, denoted as θ, which is then transmitted to the microcontroller unit;

[0058] S4. The microcontroller unit calculates the real-time window opening angle α based on preset geometric parameters and the digital angle data θ using the calculation algorithm;

[0059] S5. The wireless communication unit uploads the real-time window opening angle and timestamp to a cloud server or IoT platform via a network protocol to achieve real-time remote monitoring and analysis of the window opening behavior.

[0060] Example

[0061] like Figure 1 As shown, this invention provides a non-invasive window opening angle monitoring device based on magnetic sensing. The device comprises four modules: a mechanical transmission module, a magnetic sensing module, a control and communication module, and a power supply module. These four modules work together through electrical connections and structural coupling to complete the sensing, calculation, and data uploading of the window opening angle.

[0062] like Figure 2 As shown, the mechanical transmission module is installed at the middle of the window sash along its length. The base assembly 1 is fixed to the inner edge of the window sash with screws, and one end of it is connected to the guide tube 3 through the hinge connector 2, allowing the guide tube 3 to rotate around the hinge axis in a linear plane (XY plane).

[0063] like Figures 4-7 As shown, the short shaft section of the T-shaped rotating shaft 4 is inserted into the guide tube 3, allowing it to slide axially back and forth within the guide tube 3. The long shaft section of the T-shaped rotating shaft 4 extends vertically downward, passes through the window sill, and is inserted into the bushing housing 6, which is fixedly installed on the wall surface. The bushing housing 6 is used to constrain the rotating shaft to rotate only in the horizontal plane and limit radial movement.

[0064] The rotating magnet 5 is a cylindrical structure, embedded in the bottom groove of the long shaft of the T-shaped rotating shaft 4, with its rotation axis completely coincident with the rotation axis of the long shaft. The magnetic sensing module is installed in the fixed outer casing 7 below. The magnetic encoder 8, with its sensing surface facing upward, is set parallel to the end face of the rotating magnet 5, with a spacing maintained within 2–5 mm to ensure magnetic field sensing sensitivity and accuracy.

[0065] The control and communication module is integrated with the power supply module and encapsulated in a waterproof ABS box. The entire assembly is installed along the lower edge of the window opening on the wall. Figure 3 As shown, the control and communication module receives the signal input from the magnetic encoder 8 via a wired connection. The microcontroller unit analyzes the angle signal θ based on its built-in algorithm to obtain the current window opening angle α, and then uploads it to the cloud server or IoT platform via the wireless communication module.

[0066] The power supply module is a detachable lithium battery pack 11 with charging protection and over-discharge protection functions, which supplies power to the magnetic encoder 8 and the control and communication module through the power interface.

[0067] like Figures 8-9 As shown, to illustrate the response behavior and signal flow of the device during a real window opening process, two sets of examples are selected for explanation:

[0068] In Example 1, the window used is a common single-pane side-opening casement window. The base assembly 1 is installed in the middle of the inner frame of the window sash with screws, so that it rotates around the window frame with the window sash when the window is opened. The base assembly 1 is connected to the guide tube 3 through the hinge connector 2. One end of the guide tube 3 is hinged and fixed, allowing it to rotate in the horizontal plane. The short shaft of the T-shaped rotating shaft 4 is inserted into the guide tube 3 and can slide axially back and forth inside it.

[0069] When the guide tube 3 rotates, it drives the short shaft section to slide inside the tube, thereby causing the T-shaped rotating shaft 4 to rotate around the long axis. The long shaft passes through the lower edge of the window opening and is inserted into the bushing housing 6 fixed to the wall, which restricts its rotation to only the horizontal plane. A cylindrical rotating magnet 5 is installed at the bottom of the long shaft, facing the magnetic encoder 8 located in the lower housing 7. The magnetic encoder 8 senses the rotational changes of the magnetic field in real time and outputs an angle signal θ.

[0070] The installation parameters are as follows: the horizontal distance d from the base assembly 1 to the window sash rotation axis is 10 cm; the horizontal distance r from the long axis of the T-shaped rotation axis 4 to the window sash rotation axis is 30 cm.

[0071] When the user opens the window to a certain angle, the guide tube 3 rotates and drives the above transmission process. The magnetic encoder 8 output angle measured by the monitoring device is θ = 45°.

[0072] Furthermore, after receiving the θ value, the control and communication module substitutes it into the following calculation formula:

[0073]

[0074] Substituting the values ​​(tan(45°) = 1, cos(45°) ≈ 0.7071), Further calculations using the formula:

[0075]

[0076] Furthermore, the control and communication module packages the calculation result α = 43.91° together with the timestamp and sends it to the cloud platform via the wireless communication module.

[0077] Example 2 is similar to Example 1, except that different installation parameters were selected to accommodate a larger window sash size; the installation parameters are: d = 15 cm; r = 40 cm;

[0078] After the user opens the window, the base assembly 1 rotates, which drives the guide tube 3 to rotate. The T-shaped rotating shaft 4 rotates with the push of the guide tube 3, and the rotating magnet 5 generates a magnetic field change around the magnetic encoder 8.

[0079] Furthermore, the monitoring device measures an angle signal θ = 60°; after receiving θ, the control and communication module performs the following calculations: tan(60°) ≈ 1.732, cos(60°) = 0.5.

[0080] Further calculations can be performed by substituting the values ​​into the formula:

[0081]

[0082] The control and communication module uploads α = 47.59° and the corresponding timestamp to the cloud, completing one valid data acquisition.

[0083] The foregoing has provided a detailed description of the non-invasive window opening angle monitoring device and method based on magnetic sensing proposed in this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A non-invasive window opening angle monitoring device based on magnetic sensing, characterized in that, The device includes a mechanical transmission module, a magnetic sensing module, a control and communication module, and a power supply module. The base assembly of the mechanical transmission module is installed inside the window sash of the casement window and is connected to the magnetic sensing module fixed to the wall on one side of the window sash rotation axis. The signal input terminal of the magnetic sensing module is electrically connected to the control and communication module via a wired connection. The signal output of the control and communication module is connected to a cloud server or IoT platform via a built-in wireless communication unit using the HTTP / MQTT protocol, and is supplied with power by a wired connection to the power supply module. Both are fixed to an ABS waterproof box and installed under the window opening sill. The mechanical transmission module includes a base assembly, a hinge connector, a guide tube, and a T-shaped rotating shaft. The base assembly is fixedly installed on the window sash, and its position in the XY plane changes with the opening state of the window. The hinge connector hinges one end of the guide tube to the base assembly, allowing the guide tube to rotate in the plane about the central axis of the hinge connector. The short shaft of the T-shaped rotating shaft is inserted into the guide tube and can slide back and forth axially relative to the guide tube. The long shaft end of the T-shaped rotating shaft is fixed in a bushing shell on one side of the wall, and the bushing shell ensures that the T-shaped rotating shaft can only rotate in the horizontal plane and does not shift radially. The magnetic sensing module includes a rotary magnet and a magnetic encoder. The rotary magnet is a cylinder that is installed in a circular groove at the center of the bottom of the long axis of the T-shaped rotating shaft and rotates with it. Its rotation center axis coincides with the rotation axis of the long axis of the T-shaped rotating shaft in the spatial Z direction, so its rotation angle is the same as that of the T-shaped rotating shaft. The magnetic encoder is built into a fixed housing box installed at the lower end of the bushing housing, and a hole is reserved for the wire to pass through. The control and communication module is an integrated unit, including a microcontroller unit and a wireless communication unit. The microcontroller unit has a built-in calculation algorithm based on window geometric parameters and displacement signals to calculate the real-time window opening angle. The wireless communication unit is integrated with the microcontroller unit and supports HTTP and MQTT wireless protocols to send the real-time window opening angle with timestamps to a cloud server or IoT platform. The solution algorithm built into the microcontroller unit is based on the following geometric relationship: Wherein, α is the real-time window opening angle; θ is the reading of the digital angle signal output by the magnetic encoder; r is the horizontal distance between the center line of the hinge connector axis and the center line of the window sash rotation axis; and d is the horizontal distance between the center line of the long axis of the T-shaped rotation axis and the center line of the window sash rotation axis.

2. The apparatus according to claim 1, characterized in that, The magnetic encoder is a radial induction type magnetic encoder, whose sensing surface is set parallel to the axial end face of the rotating magnet and maintains a certain distance, detects the magnetic field change of the rotating magnet and outputs a digital angle signal θ.

3. The apparatus according to claim 2, characterized in that, The magnetic encoder maintains a distance of 2–5 mm from the rotating magnet.

4. The apparatus according to claim 1, characterized in that, The power supply module is a detachable lithium battery pack with overcharge, over-discharge and short-circuit protection circuits. It supplies power to the control and communication module and the magnetic encoder via a linear connection through a power interface.

5. The apparatus according to claim 1, characterized in that, The base assembly is installed at the middle of the window sash along its length. The horizontal distance between the center line of the hinge connector axis and the center line of the window sash rotation axis is denoted as d. The horizontal distance between the center line of the long axis of the T-shaped rotation axis and the center line of the window sash rotation axis is denoted as r.

6. A monitoring method based on the window opening angle monitoring device according to any one of claims 1-5, characterized in that, Includes the following steps: S1. When the user opens the window sash, the base assembly in the mechanical transmission module changes position in the horizontal plane through the window sash, and drives the guide tube to rotate and causes the short shaft of the T-shaped rotating shaft to slide axially in the guide tube; S2. The rotating magnet rotates synchronously with the T-shaped rotating axis and generates a measurable magnetic field change in the magnetic sensing module; S3. The magnetic encoder acquires the magnetic field change signal and converts it into digital angle data, denoted as θ, which is then transmitted to the microcontroller unit; S4. The microcontroller unit calculates the real-time window opening angle based on preset geometric parameters and the digital angle data θ using the calculation algorithm; S5. The wireless communication unit uploads the real-time window opening angle and timestamp to a cloud server or IoT platform via a network protocol to achieve real-time remote monitoring and analysis of the window opening behavior.

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